Peach component-specific IgE measurement helps to differentiate between local and systemic reactions in peach-allergic Japanese patients.

Background: Component-resolved diagnostics are used to diagnose food allergies. Currently, reports on sensitization profiles using peach-allergen components in a multicenter setting are lacking. In this study, sensitization profiling of peach allergy was performed to evaluate the clinical utility of each component specific-immunoglobulin E antibody (sIgE ab) test.

Methods: Sixty-seven patients with peach allergy were enrolled at four Japanese centers and classified into a local reaction group (LR) with only oral or pharyngeal mucosal symptoms in 36 patients and a systemic reaction group (SR) without LR in 31 patients. Serum sIgE ab tests to peach crude, Pru p 1, Pru p 3, Pru p 4, Pru p 7, and tree pollen were conducted.

Results: In the receiver operating characteristic curve analysis, Pru p 1 had the highest area under the curve (AUC) for diagnosing LR, followed by Pru p 4, which outperformed peach crude allergen. Pru p 7 had the highest AUC for diagnosing SR, with the other peach allergen components and peach crude allergen showing lower values.

Conclusions: Sensitization to Pru p 1 was associated with LRs, while sensitization to Pru p 7 was associated with SRs; approximately one-third of patients in the SR group tested negative for the titer of peach crude sIgE ab, many of whom tested positive for the titer of Pru p 7 sIgE ab. We conclude that measuring Pru p 1, Pru p 4, and Pru p 7 sIgE ab titers is useful to differentiate LRs and SRs in peach-allergic Japanese patients.